Create a web APP (NFTs related)

I would need a talented freelancer for the creation of a web app that is able to check if the visitor owns an NFT (given the smart contract address) and once the verification is completed give to the visitor the chance of claiming a "x" amount of erc20 tokens for free (as a gift).

I will take care of ERC721 token smart contract deployment, as well as erc20 creation. I will only need a web app with the mentioned settings.